Blasio shakes hands with Bratton during a news conference in Brooklyn

New York Mayor-elect Bill de Blasio (R) shakes hands with veteran police chief Bill Bratton during a news conference in Brooklyn, New York, December 5, 2013. Bratton has led departments across the country, was named on Thursday as New York City's next police commissioner, taking over a force credited with a sharp drop in violent crime but criticized for its tactics. REUTERS/Eduardo Munoz (UNITED STATES - Tags: POLITICS CRIME LAW TPX IMAGES OF THE DAY)

Bratton, 66, who was police commissioner under New York City Mayor Rudy Giuliani and has run police departments in Los Angeles and Boston, will return to the NYPD on January 1, taking over from Ray Kelly. (Reuters)